Ahmet Can Altunişik

Karadeniz Technical University · Department of Civil Engineering

Structural assessment of a historical building requires many different applications, such as in-situ observations, in-situ measurements such as minor destructive or non-destructive tests and numerical analyses. Minor destructive and non-destructive tests such as ultrasonic tests and ambient vibration tests are used to collect data from the structur...

A deep learning-based image processing study was carried out to predict the post-fire safety of historical masonry structures. For this purpose, andesite stone and lime-based mortar, which are frequently used in historical structures, were selected as test samples and the samples were exposed to high temperatures (200°C, 400°C, 600°C and 800°C) at...

Engineering software running on object-oriented programming language has been extensively used in structural modeling past 20 years. Taking their ease of use and a large area of utilization into account, these software will be used by engineers. Moreover, a number of these software increases, and many enhancements take place. Considering the develo...

This paper is based on the the post-earthquake evaluation of two heavily damaged historic masonry mosques and the investigation of the effects of near-fault and far-fault ground motions on their seismic behaviors. The Hüsrev Pasha and Kaya Çelebi mosques, located in Van province, Turkey, were exposed to two devastating earthquakes (on October 23, 2...

This paper presents damage identification and localization in laminated composite beams including multiple cracks by automated model updating. For this aim, a cantilever beam made of glass/epoxy composite laminate under six simulated damage scenarios is considered. Experimental frequencies and mode shapes of the beam are validated with those of ANS...

Historical structures are vulnerable to effect of earthquake, wind, flood, fire, etc. Considering the active seismic resources owned Turkey, earthquakes especially important threats for historical structures. Therefore, the structural response of historical structures should be investigation under seismic effects. The most important factor in inves...

Damages to structures may occur due to construction defects during various stages such as design, construction, and operation phases, or due to natural disasters during their lifetime. The Operational Modal Analysis (OMA) method enables engineers to experimentally determine the changes in dynamic characteristics of the structures that resulted from...

In this paper, modal parameters of the Eynel steel arch highway bridge are identified and the fatigue behavior of the bridge is investigated. Modal parameters were extracted from three ambient vibration tests carried out over the period since the bridge came into service. The bridge became operational in 2009, and experimental measurements were tak...

This work aims to experimentally show the effectiveness of annular cylindrical tuned liquid dampers (ACTLDs) on the classical tuned liquid column dampers (TLCDs) under the effect of inclined ground motion. For experimental measurements, a single-story model structure constituted by two plates at the top and bottom connected by four columns was cons...

Since ancient times, shelter has been one of the most basic needs of human beings. This basic need has been tried to be met by using different local materials considering both economic conditions and security understanding. The so-called “Hımış” houses formed by filling the gaps between the timber frames with masonry elements reflect the typical fe...

This study presents the experimental and numerical assessment of natural frequencies and corresponding mode shapes of cross-laminated timber (CLT) beams subjected to a series of damage cases. To this aim, two different cantilever CLT beams consisting of three layers are considered. Damages on the beam are represented by transversal notches (cracks)...

A great number of reinforced concrete building structures were damaged or collapsed during the earthquake that hit Sivrice district of Elazığ city located in the southwest of the Eastern Anatolia Region of Turkey on January 24, 2020. Magnitude of the earthquake were announced as [Formula: see text] and [Formula: see text] by Kandilli Observatory &...

This paper presents results of an experimental study that focuses on monitoring changes in dynamic characteristics of a damaged and retrofitted two-story reinforced concrete (RC) building model with poor detailing. In the study, ambient vibration tests are performed via four test setup protocols in order to monitor changes in dynamic characteristic...

This paper investigates the optimal sensor placements and capabilities of this procedure for dynamic characteristics identification of arch dams. For this purpose, a prototype arch dam is constructed in laboratory conditions. Berke arch dam located on the Ceyhan River in city of Osmaniye is one of the highest arch dam constructed in Turkey is selec...

Cultural heritage buildings are valued in contemporary societies as they reflect the lifestyles and creative achievements our predecessors. For this reason, many countries have introduced regulations to ensure conservation of their historic buildings for the future, permitting minimal changes only to their original structure and characteristics. Th...

The strong shallow earthquake with a moment magnitude (Mw) range between 6.6 and 7.0 according to different sources (AFAD, KOERI and USGS) took place at local time 14:51 on 30th October 2020, in Aegean Sea near Samos Island. According to the data given from Earthquake Department of the Disaster and Emergency Management Presidency (AFAD), the epicen...

Environmental processing, such as thermal cycling and ultraviolet (UV) exposure contribute to mechanical properties degradation of polymer composites. This paper focused on assessing the mechanical properties of triaxial carbon/epoxy (CFRP) composite laminates used in fabricating lightweight composite bridges when exposed to both thermal cycling an...

On January 24 at 8.55p.m, a major earthquake of moment magnitude Mw = 6.8 struck the Sivrice district of Elazığ, located in the southwest of the Eastern Anatolia region of Turkey. A total of 7429 buildings were severely damaged or collapsed. Unreinforced masonry buildings still represent a significant part of the residential building stock in rural...

Structural damage caused by terrorist attacks or explosions resulting from accidents is an essential crucial issue for civil engineering structures. After the explosion, heavy damage and total collapse occur in the structural carrier system, and these destructions can cause significant loss of life and property. This study aimed to determine the st...

Fire performance of load bearing elements in steel buildings such as columns and frames has major importance for structural designers. This study aims to assess the elevated temperature effect on dynamic characteristics of steel columns and frames by conducting sequential heat transfer and modal analyses. A series of finite element analyses includi...

Arch dams have delicate sections thanks to their curvature. The fact that these dams are large, costly and construction takes many years increases the importance of the structure. Mistakes and / or accidents that may occur during the construction of such structures may occur major loss of life and property. Considering the volumes, masses and slend...

The explosions caused by terrorism and/or accidental lead to serious damage and/or collapse in structures, economic losses, and most importantly endanger public safety. The blasting loads that can be larger than design loads are generally neglected in the design stage of civil engineering structures, despite these catastrophic effects. For these re...

The aim of this paper is to present the field investigation and performance assessment of the mosques and minarets constructed around the cities of Elaziğ and Malatya and their surrounding districts shortly after the earthquake (magnitude of MW ¼ 6.5–6.8 according to different institutions) that occurred at 8:55 p.m. local time on Friday January 24...

This paper presents a comparative study about the numerical and experimental system identification and model updating-based automated damage detection of concrete-encased composite column-beam connections. Four different column-beam connection types named as CBC#A, CBC#B, CBC#C, and CBC#D were considered without any changes in geometrical configura...

This paper presents a numerical and experimental investigation regarding changes in dynamic characteristics (natural frequencies, mode shapes, and damping ratios) of encased steel profile of concrete-encased composite column-steel beam connections prior to and following lateral cyclic loading tests. To do so, four specimens with different column-be...

This paper presents a numerical and experimental investigation regarding changes in dynamic characteristics (natural frequencies, mode shapes, and damping ratios) of encased steel profile of concrete-encased composite column-steel beam connections prior to and following lateral cyclic loading tests. To do so, four specimens with different column-be...

In the last 30 years, about twenty earthquakes, which were greater than magnitude M=6.0, occurred in different parts of Turkey especially close to fault lines. These earthquakes caused many buildings to be destroyed or heavily damaged, and the loss of many people’s lives. The painful lessons learned after the earthquakes resulted to the revision or...

In this study, it is aimed to be searched the effect of the rebar on the structural behavior of reinforced concrete bridges formed with the finite element method. For this purpose, the numerical model of the bridge with known dimensions, material properties and rebar configuration was modeled using ANSYS finite element analysis program. In the firs...

This study presents identification and localization of open transverse edge cracks in laminated composite beams by using vibration measurements. To this aim, a composite cantilever beam is considered under six damage scenarios. Natural frequencies and mode shapes of the beam for each case are obtained numerically by using a shear-deformable finite...

In modal testing, the quality of vibration signals and clarity of peak points to extract the natural frequencies, corresponding mode shapes and damping ratio depend on the number and location of the sensors. High measurement costs are required for structural identification and long-term structural health monitoring in large structures, which requir...

After destructive events such as earthquakes, attempts have generally been made to repair and strengthen structures using such methods as filling cracks by injection, wrapping structural elements with fiber-reinforced polymer (FRP). These applications can allow the recovery of lost structural performance. In this paper, the aim was to investigate t...

Komşu binalar arasındaki çarpışmaların yıkıcı etkilerine rağmen, literatürdeki çalışmaların genellikle analitik bir model üzerinden veya depremler sonrası yapılan gözlemler ile gerçekleştirildiği tespit edilmiştir. Deneysel çalışmalarda ise oldukça sınırlı ve küçük ölçeklerin seçildiği, çarpışmanın yapısal hasarlar üzerine olan etkilerinin çoğunluk...

The use of timber as a construction material is based on much older dates than concrete and steel. Therefore, the preservation of historical timber structures such as bridges, monuments, towers, mosques, etc. is very important for cultural heritage. The perspective of preservation for this kind of structures has been developed and has gained more i...

The effects of seismic actions on reinforced concrete (RC) structures are strongly influenced by the dynamic behavior of their materials. It is crucial to find a simple definition of the natural frequencies of reinforced concrete buildings, particularly in relation to both principal and secondary elements constructing the reinforced concrete buildi...

This paper presents a dynamic analysis considering site-specific seismic characteristics for a masonry clock tower located at the city of Çorum, Turkey according to the new Turkish earthquake code. Finite element model of the tower was modeled using ANSYS software in order to determine numerical dynamic characteristics of the structure such as natu...

Historical structures are important cultural relics which illustrate the progress of engineering development. They are a valuable source of information on construction techniques and materials selection over the centuries. However, many factors, including environmental conditions and natural disasters, contribute to damage and destruction of histor...

This paper presents an experimental study about the effects of damage on modal parameters of haunch strengthened composite column–steel beam connections. Five specimens having various composite column and steel beam connection details were constructed in order to be examined in laboratory condition. Non-destructive experimental measurements were co...

Free vibration analysis of laminated composite beams including open transverse cracks is presented by using a shear-deformable thirteen degrees-of-freedom finite element model, which considers extension-twist, bending-twist and bending-extension couplings, and the Poisson's effect. Lagrange's equation is employed to derive the equations of motion....

In the design and evaluation of the buildings, effects of earthquake-induced pounding are generally ignored, although pounding causes substantial damage or even total destruction of the adjacent buildings. Pounding between buildings may occur in various forms due to several reasons such as different dynamic characteristics, structural irregularity,...

This study investigates the performance of annular cylindrical liquid column dampers (ACTLDs) for vibration suppression of structures with experimental tests. To this aim, a shear-type frame consisting of a top and bottom plate with four columns is constructed in laboratory and is exposed to ground motion with different directions. Dynamic characte...

The objective of this paper is to evaluate the acceptable differences limit between analytically and experimentally identified modal parameters and to assess its contribution to the success of finite element model updating. To achieve this aim, three one-story reinforced concrete buildings consisting of raft foundation, columns and beams were simul...

The aim of this paper was to determine the effect of fiber-reinforced polymer (FRP) strengthening on the dynamic characteristics of reinforced concrete (RC) frames using ambient vibration-based automated model updating procedure. Four different structural conditions were examined: undamaged, damaged, "repaired with injections"; and "strengthened wi...

A parametric model is a computer representation of a design made with geometric shapes with constant and variable properties. Variable attributes are called parameters. The designer can change the parameters in the parametric model to search for different alternative solutions to the problems in the model. The parametric model is obtained automatic...

This study presents damage localisation in steel cantilever beams including multiple cracks based on changes in the modal curvature and flexibility. Natural frequencies and corresponding mode shapes of circular-hollow-sectional and box-sectional steel cantilever beams are obtained by analytical and experimental models under six damage scenarios. Ba...

Finite element models supply the simulation of the problems to obtain the structural behaviors under different loading conditions. The updating processes based on changing the uncertain parameters such as material properties, boundary conditions, meshing size etc. are made to create actual finite element models in order to represent the real condit...

This paper presents numerical modelling, modal testing, finite element model updating, linear and nonlinear earthquake behavior of a reinforced concrete building model. A 1/2 geometrically scale, two-storey, reinforced concrete frame model with raft base were constructed, tested and analyzed. Modal testing on the model using ambient vibrations is p...

This paper considers a Timoshenko cantilever beam with box cross-section including multiple cracks. Under six damage scenarios, the problem is solved analytically by the transfer matrix method, and numerically by the finite element method. Results are validated by the experimental measurements with the aid of ambient vibration tests, that use Enhan...

Ground motions in near source region of large crustal earthquakes are significantly affected by rupture directivity and tectonic fling. These effects are the strongest at longer periods, and they can have a significant impact on engineering structure. This paper focuses on the effects of long-period pulse of near-fault ground motions on the structu...

Introduction This paper aimed to determine the structural behavior of steel bearing systems by creating similarity conditions with field equations. Scaling plays a crucial role in designing experiments aimed at understanding the structural behavior of systems where experimental studies are difficult to perform due to huge structures in the professi...

As one of the most important engineering structures, arch dams are huge constructions built with human hands and have strategical importance. Because of the fact that long construction duration, water supply, financial reasons, major loss of life and material since failure etc., the design of arch dams is very important problem and should be done b...

Model updating is of significant importance in the actual analyses of real structures. The differences between experimental and numerical dynamic characteristics can be minimized by means of this procedure. This procedure can be carried out using two approaches, namely, the manual model updating and the global or local automated model updating. The...

This study is focused on the investigation for similitude the requirements between prototype and scaled models to determine the structural behavior of concrete load bearing systems. The scaling concept has been utilized in many engineering branches, has been assisted to engineers and scientists for obtain the behavior of the prototype by using scal...

Structures are built on a design and then damaged in time by natural and manmade effects, repaired and strengthened for reusing. Determination of the structural behavior is very important to avoid future disaster. Operational Modal Analysis has been widely used recently to determine the inherent modal parameters of engineering structures and give s...

Earthquakes have underlined the need for health monitoring and safety assessment of engineering structures in general and especially historical heritage. These structures can be exposed to many different loads such as earthquake and wind that may cause the deterioration and loss of structural integrity. In this study, ambient vibration-based system...

This paper gives experimental tests’ results for the control performance of Tuned Liquid Column Dampers (TLCDs) installed on a prototype structure exposed to ground motions with different directions. The prototype structure designed in the laboratory consists of top and bottom plates with four columns. Finite element analyses and ambient vibration...

In this paper, the aim was to determine the nonlinear dynamic response of historical masonry armory buildings using a validated finite element model. Eight ambient vibration tests were conducted on the building, using three different measurement test setups to extract the dynamic characteristics using the Enhanced Frequency Domain Decomposition met...

In this study, it is aimed to present engineering software to estimate the structural response of concrete arch dam. Type-1 concrete arch dam constructed in the laboratory is selected as a reference model. Finite element analyses and experimental measurements are conducted to show the accuracy of initial model. Dynamic analyses are carried out by s...

Finite-element (FE) model updating is a very effective procedure for determining the uncertainty parameters in a structural model and minimize differences between experimentally and analytically identified dynamic characteristics. This procedure can be practiced with manual and global/local automatic model updating procedures. Automatic model updat...

Restoration works have been accelerated substantially in Turkey in the last decade. Many historical buildings, mosques, minaret, bridges, towers and structures have been restored. With these restorations an important issue arises, namely how restoration work affects the structure. For this reason, we aimed to investigate the restoration effect on t...

This paper presents a detailed study on the automated model updating of a cantilever beam with box cross-section including multiple cracks for damage detection. To consider multiple crack effects, a cantilever beam with cracks is considered under six damage scenarios. Finite element models are first constituted in ANSYS software for numerical solut...